Fundus cameras, such as the commercially available "Kowa RC-2 Camera" have been available for some time and are available as portable hand held units which are adapted to produce either a 35 mm photo or a polaroid photo of the fundus of the eye. The Kowa RC-2 Camera can be used for Otorhinolargngology, Gynecology, Dentistry, Dermatology and Surgery. In all instances, the camera obtains a photo which depicts a physical condition at the instant of time of the photographic exposure. In fluorescein angiography, the camera can be used to obtain a series of black and white slides during an injection of fluorescein over a period of time. As is obvious, there is a time delay between the taking of a picture and its development; the photo depicts only a static condition; and the inspection of the eye for a period of time is limited to the operator for the period of time.
Retinal funduscopy has enjoyed widespread use in ophthalmology for the diagnosis and monitoring of ocular disease and effects of therapy with the use of color, black and white, stereo and fluorescein angiography images which are routinely obtained with 35 mm or polaroid cameras. However, limitations of these cameras include the expense, extensive training of personnel in photographic principles, costs in film developing, delay in obtaining information (or knowledge that a quality image was obtained). Also, the flash intensity required for photographic film of patients with ocular pathlogy (cataracts, inflammation, scaring, or hemorrhage in the anterior or posterior chamber) is difficult because the intense light of the flash reflects and therefore obscures the retina or degrades the image quality.
In some instances, video images are reputed to be obtained from large table top systems and use of digital technology. An expensive retinal imaging system which employs a laser (Scanning Laser Ophthalmoscopy) as the illumination light source is available. There are currently, however, no low cost, portable systems commercially available which incorporate video imaging with digital image analysis in retinal funduscopy.